iio:magnetometer:ak8975 move driver out of staging

Issues raised in last series to propose this have now been resolved
so there should be no reason this driver cannot graduate from staging.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
index e786728..7f328e3 100644
--- a/drivers/iio/magnetometer/Makefile
+++ b/drivers/iio/magnetometer/Makefile
@@ -2,6 +2,7 @@
 # Makefile for industrial I/O Magnetometer sensor drivers
 #
 
+obj-$(CONFIG_AK8975)	+= ak8975.o
 obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o
 
 obj-$(CONFIG_IIO_ST_MAGN_3AXIS) += st_magn.o